Improvement in the manufacture of fuel



UNITED STATES PATENT Orrroa MARTIN RAE, OF UIHALL,NORTH BRITAIN.

IMPROVEMENT IN THE MANUFACTURE OF FUEL.

Specification forming part of Letters Patent No. 136,263, dated February 25, 1873.

v.by-products resulting from the treatment of the products obtained in the distillation of shale to the production of artificial fuel, and of material suitable for the purposes of heating, for the generating of steam for the production of gas, and for the manufacture of coke, 850.; and consists, first, in obtaining from such before-mentioned waste or by-products what Icall abituminous mastic and, second, in the employment of the same in conjunction with coal, or with carbonaceous materials in a fine state of division, for the purposes and in the manner hereinafter indicated.

First. The before mentioned bituminous mastic may be prepared in the following manner: I take the crude shale-tar obtained in the distillation and refining of mineral oil from bituminous shale, such tar being a waste product, for which no useful purpose has hitherto been found. The tar, on being freed from sulphuric acid by means of steaming and washing in lime-water, is then run into a still, where the water and a portion of the oils are distilled off, which process renders the tar more dense and tenacious; and, beingin a state betwixt tar and pitch, 'I call it bituminous mastic. A pipe from the bottom of the still conveys the mastic to a pan where the heat is kept up to about 200 Fahrenheit. From this pan the mixing-machine, containing the coaldust, coal-powder, and other mixtures herein.-

atter described, is supplied with the requisite proportion of mastic.

Secondly. I take coaLdust, which can be obtained at a nominal price at almost every colliery in the United Kingdom. After washing it free from aluminous matter it is then dried and heated in a furnace, at the end of which is attached a mixing-machine, into which the coal-dust is passed by suitable machinery, and thoroughly mixed with about fifteen per cent. of the before-mentioned bituminous mastic. Themixing-machine delivers the composition into apressing-machine, where it is pressed into blocks of any required size or weight, and when cold it is ready for shipment, and can be used for any purpose to which natural coal is appliedsuch, for ex ample, as for the purposes of heating and for generating steam, the manufacture of gas, coke, 8:0.

Thirdly. I take small coals, coal-dross, or slack, and grind or crush it to a coarse powder by suitable machinery, after which I treat it in the manner before mentioned, and add about the same percentage of the beforementioned bituminous mastic as already described in respect of the natural coal-dust.

It should be understood that I do not limit myself to the use of any particular kind of coal or small coals, coal-dross, or slack in the manufacture of fuel. For heating or generatin g steam I prefer the dross or slack from anthracite coal; for the purposes of gasmakin g, I prefer thedross or slack from cannel or parrot coal; and for making coke I prefer the dross or slack from bituminous or caking coal. In some cases it may be of advantage to mix a certain proportion of caking with non-cakin g coal-dross or slack.

An admixture of coals is now adopted, but

in a crude manner, in the fuel or coals sup plied to the British navy, and is obtained by mixing about one ton of Welsh or non-caking coal with about one ton of Newcastle or caking coal; and this mixture is known as Baxters mixture.

Fourthly. I take either waste shale from the pits or the shale after it has passed through the vertical retorts at the oil-works, and grind or crush it'to a coarse powder by suitable machinery, after which I add about fifty per cent. of coal-dust or coal-powder to about seventy-five per cent. of this mixture. I thenadd about twenty-five per cent. of the before-mentioned bituminous mastic, and treat the mixture in the same manner as'already described.

Fifthly. I take bituminous blae, (or 1aminated, clay,) or coaly blae, (or laminated clay and coal,) which is found in connection with shale and coal. This, on being reduced to coarse powder, I mix with about fifty per cent. of coal-dust or coal-powder, to which I afterward add about twenty-five per cent. of bituminous mastic, as already described.

It should be noted here that the object of the fourth and fifth part of this invention is the production of a cheap fuel, and that in localities where waste shale or bituminous blae cannot be obtained, peat, spent tan, sawdust, or cokebreeze may be used as their substitutes.

It should be noted that in the preparation of the bituminous mastic above stated the shaletar may be used in conjunction with other tars or bitumens; but on economic grounds I prefer to use shale-tar alone. The oils obtained from the shale-tar in the preparation of the mastic, asalso the heavy oils obtained from coal-tar, may be utilized by mixing them with the coal-dust and coal-powder, which will be found to absorb from about five to seven per cent. of oil, and that blae, peat, spenttan, sawdust, and coke-breeze will absorb from about ten to about fifteen per cent. of oil without rendering the fuel friable.

Sixth. The apparatus for preparing the fuel and converting it into solid blocks maybe similar to the ordinary machines employed in the production,blockin g, or compressing of artificial fuel, or similar to a brick-making machine, with this difference, viz., that the mixing-mill and the pressing'machine should be heated to about 200 Fahrenheit, and that the fuel is made at this temperature instead of bein g made in a cold state, like bricks; and in order to economize heat in the preparation of the fuel, the apparatus is combined and connected, the coal-dust and other mixtures being partially dried and heated by the waste heat from the fines. They are then passed through the furnace by means of endless chains and scrapers, where they are heated to about 200 Fahrenheit before passing into the mixing-machine. The mixing and pressing machines may likewise be heated by the waste steam from the engine.

Figure 1 of the annexed drawing represents, in side elevation, the general arrangement of the machinery for the manufacture of patent fuel from a mixture of coal-tar and finelyground coal or peat. The tar first undergoes the process of separation into its constituent parts, those parts useful to the fuel being mixed with the coal or peat during the process of manufacture, which will hereinafter be described. a a are steamingvats into which the crude tar is placed to separate it from the acid contained in it, which is effected by heating the tar by means of a steam-coil in the bottom of the vat. hen the tar is raised to the proper temperature the acid separates from it and sinks to the bottom, whence at intervals it runs off, by a pipe for that purpose, into store-tanks situate in the base of the building or in any other suitable position. During the process of separating the acid from the tar, a small quantity of oil also contained in the tar evaporates and passes into the waste-oil vats b b, where it is caught and stored. The steaming-vats are made of wood lined with lead; the steam-coil is also made tion of the vat with a steam-jacket.

of lead, and the sluice-valve of patent metal, to resist the corrosive action of the acid'. Af-

ter the acid has been separated from the tar,

the sluice-valve or valves are opened, when the tar passes into the distilling-vat or vats,

one of which is shown at G, where the tar and oils are separated. This is accomplished by heating to the proper temperature by means of a pair of steam-coils, oneplaced above the other, and by surrounding the cylindrical por- The coils are fed with steam direct from the boiler; the jackets are heated by the steam that has passed through the coil previous to its escaping into the atmosphere. WVhen the tar has reached the proper temperature the oil will begin to evaporate and pass into the condenser shown in end view at d, and will continue to do so till the whole of the oil has passed over. The tar is then run off into the mastictank f, and is ready for mixing with the coal or peat at the required temperature. The oil is condensed by means of the condenser d, formed by a number of vertical pipes arranged side by side, and connected together in pairs at the top ends; the lower ends are secured into a long narrow tank having'partitions so arranged that the oil is made to circulate through the entire length of tubes or pipes, if necessary, while it readily allows the coir densed oil to fall at any point and run off into the oil-store tank at beneath. water can be passed over the outside of the condensertubes, if necessary. The coal is thrown into the hopper e, which is provided at the bottom with a double set of fluted rollers for crushing the coal to the proper gage; the-outside rollers are adjustable; After the coal has been reduced to the proper size it falls "into the heater g, which consists of a strong castiron box, the under side of which is heated by the waste gases from the boiler-fines. A pair of rollers, one at either end, carries a couple of flat-link chains provided with scrapers, which extend across the box, and are placed aboutsix inches apart, the top edge standing about one and one-half inch above the bottom of the box. The scrapers propel the finelyground coal or peat over the heated plates, where it is heated to the required temperature. The pipe H is connected with the oil-tank, and feeds the, proper quantity of oil to the extent of about five per cent. of the weight of the fuel manufactured, and is mixed with it directly it is ground. At the end of the heater is placed a vertical pug-mill or mixer, J, for mixing the oil, tar, and coal or peat. This machine consists of a strong cylinder, through the center of which passes a wrought-iron shaft provided with a number of spiral knives for mixing the fuel and forcing it to the chute and feeders J. This machine is geared to the engine direct. Above the pug mill is placed a cock, h, having six branches for supplying and distributing the tar, which is added to the coal at this point to the amount of about ten per cent. of the weight of the coal. After the coal has been thoroughly mixed, it is forced into the molds on the fuel-press 70. These molds are made in sets of three, and linked together to form a chain, which works over a pair of octagon drumsthe twooutside molds making blocks twelve by six by six inches, and the inside ones six by six by six inches. After the molds have been filled they are passed under the double-acting ram L, the downstroke of which presses the fuel to its proper density, and, at the same time, forces out the blocks from the molds immediately under it, the last half of the upstroke giving motion to the molds to bring them under the ram, and also propelling the finished blocks through the drying-oven L, should it be found advisable to use an oven. An inclined plane prevents the blocks falling too rapidly onto the traveling-table M. The traveling-table con-' sists of a couple of flat-link chains, connected together transversely by small round rods, upon which the blocks of fuel rest. The oven is placed between the boilers, and is heated by the gases from the furnaces. After the heated gases have traversed the length of the boiler once, they pass between the oven-plates, and then back again under the bottom of the boiler, whence they pass under the'heater to the chimney. The hydraulic ram on the fuelpress is supplied with water from an accumulator, consisting of a strong cast-iron cylinder fitted with a ram loaded to the required pressure at which the ram works. A small pumpin gen gine is fixed to the accumulator for keeping it fully charged. The valve of the pressram is worked by the engine, and is so ar-' ranged that the number of strokes per minute can be varied at pleasure.

Having now described the nature of my said invention, and having explained the manner of carrying the same into effect, I would have it understood that I do not confine myself to the exact proportions or the precise details herein set forth, as they may require to be varied to suit the character of the materials employed; for example, a lean' non-caking dross will absorb more mastic oleaginous matter than fat caking dross, 820. When peat is used in the place of coal, it is first passed into the roller-press 0 by the hopper a, (Fig. 2 of my drawing,) where the water is squeezed from it. After this has been done, it passes into the separator 19, where it is broken up and further dried. It is then raised to a hopper on the top floor by means of an elevator, to which it is conducted by the chute q and is discharged into a chute above, which delivers it into the hopper 6 before referred to. The separator consists of a number of wroughtiron rings connected together on the inside with fiat wrought-iron bars, and forms a basket, on the outside of which bars, bent in a zigzag manner, are riveted. These fit into similar bars fastened to the casing. The basket is driven at a high velocity, the casing remaining stationary. The peat passed into the basket is caught by the centrifugal force and driven through the apertures in the basket, where it comes in contact with the bars fastened to the casing, and is dashed to pieces; after which it passes into the hopper and treated in a similar manner to the coal.

Claims.

1. The preparation of bituminous mastic from shale-tar, and the use and application of the same in conjunction with either coal-dust, small coal, coal-dross, coal-slack, bituminous shale, spentshale,bituminous blae or coaly blae, peat, spent tan, sawdust, and coke-breeze, all by preference in a state of division, or with mixtures of two or more of the same, for the preparation of fuel, as herein set forth.

2. The combination and arrangement of machinery or apparatus for the manufacture of artificial fuel, substantially as hereinbefore v described, and illustrated by ;my drawing.

In witness whereof I have signed my name to this specification in the presence of two subscribing witnesses.

' MARTIN RAE.

Witnesses:

OHAs. MILLs,

47 Lincolns Inn Fields, London; FREDK. U. DYER,

47 Llncolns Inn Fields, London. 

